Caspase-dependent ceramide production in Fas- and HLA class I-mediated peripheral T cell apoptosis.
We recently demonstrated that the engagement of HLA class I alpha1 domain induced Fas-independent apoptosis in human T and B lymphocytes. We analyzed the signaling pathway involved in HLA class I-mediated apoptosis in comparison with Fas (APO-1, CD95)-dependent apoptosis. The mouse mAb90 or the rat YTH862 monoclonal antibodies which bind the human HLA class I alpha1 domain induced the production of ceramide which was blocked by addition of the phosphatidylcholine-dependent phospholipase C inhibitor, D609. Furthermore, HLA class I-mediated apoptosis involved at least two different caspases, an interleukin-1 converting enzyme-like protease and another protease inhibited by the CPP32-like protease inhibitor Ac-DEVD-CHO. Despite similarity between Fas and HLA class I signaling pathways, we failed to demonstrate any physical association between these two molecules. We also report that the pan-caspase inhibitory peptide zVAD-fmk, but not Ac-DEVD-CHO and Ac-YVAD-CHO, inhibited decrease of mitochondrial transmembrane potential and generation of ceramide induced by anti-HLA class I and anti-Fas monoclonal antibodies, whereas all three peptides efficiently inhibited apoptosis. Altogether these results suggest that signaling through Fas and HLA class I involve caspase(s), targeted by zVAD-fmk, which act upstream of ceramide generation and mitochondrial events, whereas interleukin-1 converting enzyme-like and CPP32-like proteases act downstream of the mitochondria.
Genestier
L
L
Laboratory of Immunology, INSERM U80 UCBL, Hôpital E. Herriot, 69437 Lyon, France.
Prigent
A F
AF
Paillot
R
R
Quemeneur
L
L
Durand
I
I
Banchereau
J
J
Revillard
J P
JP
Bonnefoy-Bérard
N
N
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D017209:Apoptosis; D001952:Bridged-Ring Compounds / Q000494:pharmacology; D020170:Caspase 1; D053148:Caspase 3; D020169:Caspases; D002518:Ceramides / Q000096:biosynthesis*; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003572:Cytochalasins / Q000494:pharmacology; D015395:Histocompatibility Antigens Class I / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D008928:Mitochondria / Q000187:drug effects; D008954:Models, Biological; D009636:Norbornanes; D019319:Okadaic Acid / Q000494:pharmacology; D009842:Oligopeptides / Q000494:pharmacology; D018892:Proton-Motive Force / Q000187:drug effects; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*; D013859:Thiocarbamates; D013871:Thiones / Q000494:pharmacology; D019014:fas Receptor / Q000378:metabolism*
D000590:Amino Acid Chloromethyl Ketones; D000911:Antibodies, Monoclonal; D001952:Bridged-Ring Compounds; D002518:Ceramides; D015853:Cysteine Proteinase Inhibitors; D003572:Cytochalasins; D015395:Histocompatibility Antigens Class I; D009636:Norbornanes; D009842:Oligopeptides; D013859:Thiocarbamates; D013871:Thiones; C099158:acetyl-aspartyl-glutamyl-valyl-aspartal; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D019014:fas Receptor; C096429:L 709049; D019319:Okadaic Acid; C046498:tricyclodecane-9-yl-xanthogenate; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases; D003546:Cysteine Endopeptidases; D020170:Caspase 1